Cycling is a very popular activity for both recreational riders and racing enthusiasts alike. Professional cyclists and triathletes are earning large sums of money through races, sponsorships, and advertisements. Moreover, cycling provides many health benefits for average riders in that it strengthens various muscle groups along with providing aerobic and anaerobic exercise to the user. Furthermore, physicians and physical therapists are turning to stationary cycle devices to rehabilitate patients from automobile, athletic, or work-related injuries. Because of this, there is a demand for indoor, stationary exercise trainers that simulate actual outdoor riding so that professional and recreational cyclists may train or exercise regardless of the weather, and that patients can rehabilitate injuries in the presence of their physicians and physical therapists.
Various stationary cycle trainers have been presented to address this need. Conventional stationary cycle trainers simulate the characteristics of outdoor training by applying a variable resistance device to provide resistance against the pedaling of the rider. The variable resistance device mimics the resistances a rider would face during actual outdoor training such as wind resistance, rolling resistance, and resistances due to riding over varying terrain. Recently, the use of “eddy current” trainers have achieved widespread use due to their ability to simulate the resistance (loads) felt by riders during actual riding.
Further advancements in “eddy current” trainers allow for the monitoring and evaluation of the rider's or patient's performance during the exercise session. These trainers generally use a microprocessor/sensor arrangement to calculate several session parameters, such as heart rate, energy exertion, time elapsed, and distance. The microprocessor is also connected to an electric drive circuit that energizes the electromagnets at predetermined times and power levels in order to simulate changes in terrain. An eddy current trainer that uses electromagnets to simulate real life bicycling road conditions, and that uses a microprocessor to evaluate the user's performance, is sold under the trademark COMPUTRAINER by Racermate, Inc., Seattle, Wash.
Although the use of electromagnets and microprocessor has dramatically improved such “eddy current” trainers, there are still limitations that exist. For example, it is well known that mechanical and electrical systems can drift out of initial calibration, thus generating erroneous data. This is important to a majority of the riders that use these trainers, especially professional athletes, since they need to know if the session parameter data received during the exercise session is still accurate. At the present time, the only method to determine if the trainer is still within a predetermined margin of error of its initial factory calibration is to return the trainer to the factory for testing, which can be prohibitively expensive.